Biometric authentication refers to the identification of humans by their characteristics or traits. Biometric identifiers are often categorised as physiological or behavioural. Physiological biometric identifiers relate to unique identifiers associated with an individual human's physiology. DNA and fingerprints are examples of such physiological biometric identifiers. Behavioural biometric identifiers relate to an individual's behaviourisms, such as gait and voice. The field of behavioural biometrics is commonly referred to as behaviometrics.
Historically signatures have been used to authenticate documents. The presence of the signature on a document is interpreted as an indication that the signee adopts the intentions and/or terms set out in the document. For example, the presence of an individual's signature on a legal document, such as a lease, indicates that the individual is bound by the legal clauses set out in the document. A signature may comprise one or more symbols, or other distinctive markings, associated with the identity of the person drawing the symbols and/or markings, such as a stylized script of letters that may spell the person's name. The authenticity of the provided signature may be verified by comparing it to a template signature for consistency. This may effectively be an image comparison process, which seeks to determine whether the provided signature and the template signature are sufficiently similar in appearance. Any visual discrepancies may be indicative of a fraudulent signature.
Existing identity verification processes (also referred to as signature verification processes) often rely on signature verification and can be relatively insecure. For example, in order to compensate for a human's inability to reproduce identical graphical copies of their signature, the image comparison is approximate, which can limit the accuracy of the signature verification process. The confirmation of identity is thus approximate and based on the image comparison. In addition, many known signature verification processes are susceptible to fraudulent users, as it is relatively straightforward for an expert forger to graphically reproduce a visually-similar signature that is capable of generating a false positive verification result. For these reasons, many documents and/or transactions would benefit from a more robust and secure form of identification verification. For example, in the case of high value documents and/or high value transactions, often the presence of a trusted third party vouching for the identity of the signee is required—one of the functions of a notary public—and/or alternative identification verification means are required.
Due to the ever growing use of electronic communication, there are also systems that provide an electronic equivalent of the traditional signature and use digital means to validate a user's identity on the basis of a provided signature.
A commonly implemented method of digital identity verification relates to the use of a password/passcode, in which a unique, confidential alphanumeric code is used to uniquely identify a person to a system. Such verification systems are often inconvenient since they require that the user remember their unique alphanumeric identification code. The security of such systems is also dependent on the maintained confidentiality of the identification code.
Certain existing electronic signature verification systems suffer from several shortcomings which limit their practical utility in identification verification systems, and compromise the level of security provided. Such systems operate by comparing a user's received signature with a user's pre-stored signature template. This comparison process is commonly an image comparison process, wherein geometric similarities are identified. Such verification systems analyse the provided signature for the presence of specific geometric objects present in the template signature. Various object matching techniques may be used. A positive signature verification result is returned where any identified geometrical discrepancies between the signatures lie within a predetermined and allowable threshold value. Otherwise, a failed verification result is returned. This verification process is often an approximate statistical process, which analyses the statistical graphical similarity between a reference signature (the template signature) and a provided signature by identification of geometrically similar objects present in both signatures.
Electronic signature verification systems that are reliant on a statistical analysis of the graphical similarities between signatures may be susceptible to fraud by expert forgers capable of generating signature forgeries that are visually sufficiently similar to the signature template. Therefore, when used as security devices, known electronic signature verification systems provide a limited level of security.
Different embodiments of the present invention have different objects, but at least one object of one embodiment is to provide a more robust electronic signature verification method and system using behaviometrics, which may be used for digital identification purposes, and mitigates at least some of the shortcomings of existing electronic signature verification systems.